1. Field of the Invention
The present invention generally relates to an image edge correction apparatus and method, and more particularly, to an image edge correction apparatus and method whereby the contour of an edge portion of an image is enhanced while reducing noise in a plane portion of the image.
2. Description of the Related Art
Generally, an image captured by a digital camera for a cellular phone or a low-pixel popular digital camera is not clear due to a small-size image sensor, a small-size lens, and a simplified function of an image processing integrated circuit (IC) for cost reduction. In particular, the edge of a subject included in an output image, i.e., the contour of the image is blurred. The contour of the image means an outline where the position, shape, and size of an object change. The contour of the image contains much information about the image and exists in a position where the brightness of the image changes from a low value to a high value or vice versa. To solve blur in the contour of the image, edge enhancement has been suggested.
FIG. 1 is a flowchart conceptually illustrating a conventional edge sharpening method for edge enhancement.
As illustrated in FIG. 1, in the conventional edge sharpening method, an image signal is received in operation 11 and is stored in the unit of a frame in operation 12. In operation 13, a luminance component is extracted from the stored image frame in order to generate a luminance image. A high-pass filter is applied to the entire luminance image in operation 14. An edge-enhanced pixel is obtained by combining a pixel passing through the high-pass filter with an original image, thereby generating an improvement image in operation 15. An image reconstruction process is performed in order to reconstruct the original image in operation 16. According to the conventional edge sharpening method, operations 11 through 16 have to be repeated for all pixels in order to perform edge enhancement for the entire image.
The conventional edge sharpening method uses a fixed filter for improving the sharpness of an image. However, due to the use of the fixed filter, characteristics of various sensors cannot be flexibly exploited and the sharpness of an image cannot be improved adaptively according to a change in an external environment.